“If you look at a map of global warming, the most eye-catching place where it’s not warming is the region south of Iceland, the sub-polar north. People are theorising that is evidence of the overturning circulation slowing down. 

... There are a lot of questions right now about which way it’s going to go, are the Arctic and sub-polar regions going to get warmer or are they going to get colder? The Arctic right now is the place where we’re seeing the most warming. We’re losing sea ice, glaciers are melting, you can see pictures of polar bears on very small icebergs. That’s one of the reasons that the Arctic is feeling the effects of climate change, of global warming the most.

However, if the the overturning circulation in the Atlantic slows down drastically, then you might actually expect that the Northern Hemisphere might get colder.

Temperatures are increasing, they’re not changing the same everywhere. In that specific part of the North Atlantic, they are decreasing, which is still climate change. You might think, “Oh, it’s getting colder here. So what’s the big problem?” But actually that’s a symptom. The current is misbehaving, and something’s going wrong in the system that we rely on.”